in_value = int(input())

if in_value >= 30:
  print("Yes")
else:
  print("No") in_value = int(input()) in_value int(input()) int input() input if in_value >= 30:
  print("Yes")
else:
  print("No") in_value >= 30 in_value 30 print("Yes") print "Yes" print("No") print "No" in_value = int(input()) int(input()) in_value
in_value = int(input())

if in_value >= 30:
  print("Yes")
else:
  print("No")